1. Field of the Invention
The present invention relates to a motor-driven camera in which film winding/rewinding operations and other operations are efficiently and effectively carried out by two motors provided in the camera.
2. Description of Related Art
Recently, a new type of film cartridge for use in cameras has been proposed. In a conventional film cartridge used in cameras, a film leader or tongue is placed outside of the film cartridge by a small amount, in advance, so as to be manually drawn out and engaged with a film take-up spool provided in the camera when the film cartridge is loaded. However, in the new type of film cartridge, all the film, including the film leader, is housed inside the cartridge before use (in an unexposed state). When in use, a slot which is formed on the cartridge and is closed by an openable door when not in use, is opened by opening the openable door and subsequently the film leader comes out of the slot by a rotation of a spool in the film cartridge. Such a new type of film cartridge is disclosed in U.S. Pat. No. 5,122,820 or U.S. Pat. No. 5,296,887.
In a camera using such a new type of film cartridge, in the case where various kinds of operations such as film winding/rewinding, shutter charge, quick-return mirror up/down operations, etc. are carried out using motors, it is very important to establish beforehand a space-efficient arrangement for the motors in the camera and an efficient allocation of the motors, i.e., which motors are to be allocated to which operations, so as not to increase either the number of motors or the size of the camera.
In recent years, the majority of cameras sold have been so called automatic cameras in which film winding/rewinding operations are performed automatically using a motor. In a conventional automatic camera a regular wind control is usually adopted in which a film is wound by one picture frame through a rotation of the film take-up spool of the camera each time a picture is taken. Another type of wind control, known as a prewind control, is also known in which all the film is wound in advance immediately after the film cartridge is loaded in the camera. With this type of control, each time a picture is taken, the film is rewound back inside the film cartridge by one picture frame, due to a rotation of the spool in the film cartridge.
In a conventional automatic SLR camera, not only film winding/rewinding operations, but also quick-return mirror up/down operations, need to be automatically performed using a motor. Therefore, it is necessary to provide a plurality of motors. However, this complicates driving control.